Photocatalytic Conversion of Carbon Dioxide into Valuable Chemicals in “Artificial Photosynthesis” Systems: Recent Developments and Patents Review

Our current economic and industrial growth relies on fossil fuels that can be easily and economically converted into energy and useful chemicals, but this economic model is endangered by the depletion of these resources and by environmental problems as the emission of CO2 and other greenhouse gases. To solve this dilemma, we can find inspiration in natural photosynthetic organisms that consider CO2 as a carbon source and not as a waste, and power its transformation into valuable chemicals with renewable solar energy. To transform this vision into a practical and affordable reality, several challenging scientific and technical questions must be solved, including: the cost effective production of stable photocatalysts, the elucidation of the mechanisms of formation of useful compounds from CO2, or the implementation of the technology using scalable reactor concepts. This article presents a review of recent developments and patents related to “artificial photosynthesis” systems, covering key aspects such as the transition from macro-sized photo-electrochemical cells to nanostructured catalyst, the combination of these catalysts with organic or inorganic light sensitizers in order to extend the light wavelength range in which they are active, and the design of artificial photosynthesis reactors.